Intravitreal injection related endophthalmitis
Reviewed by Jayavani Myneni

This article reviews the incidence, clinical findings, risk factors, management and visual outcomes in intravitreal injection related endophthalmitis. Incidence of this complication is reported to be in the range of 0.038% to 0.065% (1 in 2000-3000 injections). Patients present typically within five days with reduced vision, pain and photophobia. Data shows a positive culture rate of 52-59.6% with the commonly isolated organism being coagulase negative staphylococcus. Rate of streptococcus isolation is higher (25% to 30%) in contrast to cataract surgery related endophthalmitis where it is 8.2-9%. This has been attributed to passage of respiratory tract flora during the injection procedure. The management of these patients by most practitioners was based on the general guidelines from Endophthalmitis Vitrectomy study. Most cases can be managed with vitreous tap and intravitreal antibiotics. Visual recovery was measured as percentage of patients recovering their pre-injection visual acuity. This outcome was dependent in part on the causative organism. Poorer outcomes were found in cases where streptococcus was isolated. One of the studies suggest that contamination of the injection site with upper respiratory flora such as streptococcus occurs when the patient, nurse or physician talk or cough during the procedure. The authors recommend that this be avoided. But there is no definitively proven benefit with the use of facemask. The use of perioperative antibiotic drops is not supported by enough data and the suggestion is that their widespread use may breed resistance in organisms. However, povidone iodine is consistently found to be effective. Bimanual assisted lid retraction is reported to increase patient comfort when compared to lid speculum without increasing any risk from lash contamination. Investigations of endophthalmitis reported after bevacizumab injections revealed that contamination occurred during the preparation of syringes at compounding pharmacies. This 
review article is a good summary of the current evidence and practices in management of intravitreal injection related endophthalmitis. 

Endophthalmitis after intravitreal injections of anti-vascular endothelial growth factor medications.
Haddock L, Ramsey DJ, Young LH.
SEMINARS IN OPHTHALMOLOGY
2014;29(5-6):257-62.